Saxagliptin is chemically known as (1S3S,5S)-2-[(2S)-2-amino-2-(3-hydroxy-1-adamantyl) acetyl]-2-azabicyclo[3.1.0]hexane-3-carbonitrile having the chemical formula

Saxagliptin is marketed under the trade name Onglyza by Bristol-Myers Squibb for the treatment of Type-2 diabetes.
Saxagliptin or its pharmaceutically acceptable salts were first disclosed in the U.S. Pat. No. 6,395,767 (herein after referred as U.S. '767) by Bristol-Myers Squibb in the Example 60. The patent U.S. '767 discloses the process for the preparation of Saxagliptin as depicted in the Scheme I:

The aforementioned Scheme for preparing Saxagliptin employs lithium aluminum hydrate pyrophoric solvents and harmful reagents like potassium cyanide whose usage are not affordable in commercial process. These reagents are not environment friendly and the process is not commercially suitable for the preparation of Saxagliptin in large scale.
The patents U.S. Pat. No. 7,420,079, U.S. Pat. No. 7,186,846 and U.S. Pat. No. 7,205,432 disclose the process for the preparation of Saxagliptin overcoming the disadvantages of U.S. '767. Therefore, there exists a need for a novel, environment friendly, efficient and commercially viable process for the preparation of Saxagliptin.